Storage tank



ct. w, 1944. H. R- POWELL 2,359,937

STORAGE TANK Filed Sept. 28, 1942 2 Sheets-Shet 1 INVENTOR H432 Y E pow/ELL BY fl 9" W J ATTORNEYS H. R. POWELL STORAGE TANK Patented Oct. 10, 1944 UNITED STATES PATENT ()FFICE' 4 Claims.

This invention relates to storage tanks, and

it has reference more particularly to the construction of wooden tanks of large diameter; it being the principal object of this invention to provide novel details in the construction of a wooden tank that will have many advantages over present-day types of storage tanks from the standpoint of assembly, maintenance, and initial cost of construction.

More specifically stated, the objects of the present invention reside in the novel features of design and construction of circular wooden storage tanks of large diameter, erected upon a concrete base and footings, and wherein the side walls of the tank are built up of superimposed, horizontal staves; each of which staves comprises a plurality of wooden planks of like dimensions placed end to end, and sprung to the proper arc of curvature, and their juxtaposed end portions joined by the application of splice cleats thereto. The assembly of staves of the tank is maintained by vertical posts, or uprights, in paired relationship at inside and outside of the walls, anchored at their lower ends to the base or footings of the tank and joined together at their upper ends.

It is also an object of the invention to provide novel means in connection'with the paired uprights or posts which hold the staves in alinement, whereby to clamp and hold the staves tightly together, thus to insure against joint leakage, and to maintain rigidity and durability of construction.

Still another object of the invention is to provide novel means for the sealing of the joint between the concrete base of the tank and the wooden side walls to insure against leakage along this line.

Other objects of the invention reside in the details of construction of the various parts, in their combination, modeof assembly and use, as will be hereinafter fully described.

In accomplishing the above mentioned and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein- Fig. 1 is a plan view of a storage tank embodied by the present invention; a second of the side wall structure being omitted in order to better disclose details of the concrete base construction.

Fig. 2 is an enlarged, horizontal sectional detail of a segmental portion of the tank wall, taken on the horizontal line 2--2 in Fig. 3.

Fig. 3 is an enlarged, detail of a segmental portion of a tank wall as seen in side view.

Fig. 4 is an enlarged sectional detail of the tank wall on the vertical line 4-4 in Fig. 3, with a part broken away to reduce the height of the View.

Fig. 5 is a similar view taken on line 55 in Fig. 3.

Fig. 6 is an enlarged sectional detail on line 2-6 in Fig. 3. 7

It is anticipated that tanks of the present I kind can be fabricated in factories and shipped to various points of use for assembly, and that in the assembly of parts, skilled or specialized labor will not be required.

The present construction is adapted more particularly to tanks of large diameter, for example, tanks having a diameter of sixty feet or more, suitable for the storage of water, oil or other liquid. The particular advantages residing in the herein disclosed details of construction are thought to be due to provision for the building up of such tanks with wooden, circular staves, disposed horizontally and superimposed in required number to give the necessary or any desired height to the tank wall. Each stave, as herein used, is made. up of wooden planks, of selected lumber, joined end to end and sprung to the proper arc of curvature; the present tank, by reason of the use of horizontal staves, being differentiated from the usual types of wooden tanks having walls made up of vertical staves held in place by encircling bands or hoops.

It is not the intent to place any limitation either on the diameter of the tank, or the dimension of beams and posts except as required to be consistent. Manifestly, the minimum diameter that such tanks can be made would be determined to some extent at least by the extent to which the planks which compose the side walls might be sprung.

Referring more in detail to the drawings- In Fig. 1, ll] designates a tank in its entirety as embodied by the present invention. The various parts of this tank are better shown in the several views comprising the remaining figures of the drawings. The base, or bottom wall I I of the tank is composed of concrete and is formed integral with a footing l2 of substantial depth upon which the side walls of the tank rest. The relative thickness of base and footing for this present construction is shown in Fig. 4, but this may vary in accordance with conditions or requirements.

In the building of the present tank, the base H and the integral footing l2 are first poured and the concrete thereof allowed to set. In the making of the footing portion, which continues flush with the top surface of the bottom wall, it is formed in its top surface with a continuous, circular channel or groove 15 of substantial depth corresponding in its diameter to that of the tank, and at regular intervals of spacing, this channel is formed with widened portions of definite length, as has been shown at IS in Fig. 1. The channel [5 is somewhat wider than the maximum thickness of staves so that the lower edge portion of the bottom stave may be easily received therein, and the portions l6 of the channel are of such width as to receive the plank ends and to give room for the application of joining cleats thereto, when it is desired that they be assembled in the groove. It is possible, however, to completely assemble the parts of the lower stave, then to drop it into the circular groove, but sometimes this is not advantageous.

The side walls of the channel l5, as shown in Fig. 4, are somewhat beveled as at H, and by reference to Fig. 5, it is to be noted that the longitudinal side walls of the widened portions l6 of the channel are likewise beveled as at l8 and IS.

The wooden side walls of the tank are built up to the desired height by imposing the staves successively, one upon the other, as they are constructed. Each stave is composed of the required number of wooden planks 20, placed end to end and joined rigidly together by the wooden cleats 2| and 2|, located respectively at inside and outside of the end portions of the joined planks, and united therewith by a suitable number of bolts 24 that are extended through the overlapping end portions of the planks and cleats, as shown best in Figs. 5 and 6.

These planks, when necessary or desired, may be steamed to facilitate their being bent to the required curvature and they may in such instances be permanently set in arcuate form.

In a tank of thirty foot radius, it has been found quite practical in the building up of the staves, to use planks that are twenty feet long,

and in the assembly of successive staves,one upon It is desirable that the staves be formed in opposite longitudinal edges with tongues and grooves adapted to be interfitted to prevent leakage and to add strength to the structure. Such interfitting of tongues and grooves is shown at 28 in Figs. 4 and 5.

The superimposed staves, as built up, are held in place by paired vertical posts 3030, located at regular intervals of spacing about the tank and registering at inside and outside of the tank wall, with their lower ends anchored to the footing and their upper ends extended somewhat above the tank wall, and joined together by bolts 35. It has been found practical,- where planks twenty feet long are used in the construction of staves, to place the pairs of posts 30-40 five feet apart.

In the joining together of the upper ends of the posts, the bolts 35 are extended through an interposed abutment and spacer block 36 of end grain wood, placed lengthwise of the posts. This spacer 36 is square cut on its lowerend and provides a certain amount of space between its lower end and the top edge of the side wall of the tank for the insertion of coacting wedge blocks 38--38, as seen in Fig. 3.

As a detail of construction, it is to be observed by reference to Fig. 1, that the footing is provided at the designated intervals for erection of posts 3l3!l, with sockets 4040 at inside and outside of the channel I5. Also, it is shown that the lower ends of the posts are anchored to vertical straps M of iron that are inserted in the sockets and then secured by filling the sockets with concrete. The upper end portions of the straps 4| overlap the outside of the lower end portions of the posts, and are secured thereto by lag screws 45 and one through bolt 46 as seen in Fig. 4. In this present construction, the inside posts 30 rest flatly at their lower ends on the base ll while the outside posts are contained within sockets 40.

Another detail of construction is to be found in the use of the ordinary type of split ring 5|] to strengthen the connections provided between the stave ends and the splice members 2|. These split rings, as seen in Figs. 5 and 6, are countersunk within theengaged surfaces of the overlapping planks and splices and the connecting bolts 24 extend centrally therethrough, as has been illustrated. A similar use of split rings 5| is employed in the fixing of the blocks 36 in place, and in the attachment of the straps 4| to the posts, the bolts and lag screws are passed through shear plates of suitable kind, as indicated at 52.

In the construction of the tank, the planks 20 for the lower stave are placed in the channel l5 between the anchored vertical posts 3030. Then the cleats 2|2l are applied to join the ends of the planks and are clamped tight. Then the other staves are successively fabricated and properly superimposed until the tank wall is of the desired height. In this assembly of staves, the end joints between planks are staggered as shown in Fig. 3. After the assembly of staves has been completed, the wedge blocks 3838 are inserted between the lower ends of the spacer and abutment blocks 36 and the top edge of the side wall of the tank, and are driven togetherso as to operate to tighten all the staves together. These wedge blocks may be further tightened during use of the tank, to take 'up any looseness due to shrinkage that may occure in the staves.

After all staves are in place, the joint is filled about the inside with calking 25 and at the outside the groove is filled with grout 26. The bevel ll of the groove l5 and beveled wall l8 operate under pressure of liquid in the tank to compress the calking' to maintain the joint sealed. The undercut bevel of the outside wall surfaces of the groove, as at H], locks the grouting in place.

The advantages in this type of construction are due to the provision for fabrication from parts of standardized dimensions, thus reducing cost of manufacture, and providing for speed in erection and reduced cost of erection. Furthermore, the materials for this type of construction may be fabricated at one place and shipped for the other, to form the side walls of the tank,

posts arranged at intervals and in pairs along the side walls at inside and outside thereof, and having their lower ends anchored to the base wall and their upper ends extend above the top edge of the tank wall, abutment blocks fixed between the upper ends of the paired posts and wedge blocks applied between the abutment blocks and top edge of the side wall to tighten the staves together. I

2. In a tank of the character described, a horizontal base wall formed in its top surface with a continuous circular groove, a plurality of circular, horizontally extending staves disposed concentrically one upon the other to form the side walls of the tank, the lower stave being disposed in said base wall groove, joint sealing material applied within said groove, posts arranged in pairs and at spaced intervals along the tank wall at inside and outside thereof; said posts being fixedly anchored at their lower ends to the base wall and extending at their upper ends above the top edge of the tank wall, abutment blocks fixed between the upper ends of the paired posts, and wedge blocks applied between the top edge of the tank wall and the abutment blocks to tighten the staves together. I

3. A tank of the character described comprising a horizontal base wall formed in its top surface with a continuous circular groove, a plurality of circular horizontally extending staves disposed concentrically, one upon the other, to form the side walls of the tank; the lower stave being disposed in said groove of the base wall and said groove having the side wall thereof that is at the inside of the tank wall, outwardly and downwardly beveled, and a compressible joint sealing material applied within the groove and adapted to be wedged therein by pressure thereagainst by liquid in the tank.

4. A tank of the character described comprising a horizontal base wall formed in its top surface with a continuous circular groove, a plurality of circular horizontally extending staves disposed concentrically, one upon the other, to form the side walls of the tank; the lower stave being disposed in said groove of the base wall and said groove having the side wall thereof that is at the inside of the tank wall, outwardly and downwardly beveled, and a compressible joint sealing material applied within the groove and adapted to be wedged therein by pressure thereagainst by liquid in the tank; the side wall of the groove that is at the outside of the tank wall being beveled outwardly and downwardly to form a dovetailed lock for the sealing material at that side.

HARRY R. POWELL. 

